These same issues caused by transmitters stomping on each others' signals are also a massive issue in the 5.8 GHz band, but to a far lesser extent due to the vast array of different non-overlapping channels available for use. This feature allows the RC system to dynamically switch between frequencies on the fly as needed, without any input required from the pilot. The solution to this problem, which has been implemented in the vast majority of all 2.4 GHz RC systems, is to implement frequency-hopping.
( does this sound familiar? XD) This issue was worsened by the fact that the 2.4 GHz band we are allowed to use doesn't allow for very many non-overlapping channels and because the 2.4 GHz band is used by many other different kinds of devices and appliances which can also step on RC transmitters' signals. All of a sudden, people would begin turning on their transmitters at the flying field and their transmitter would talk over other people's transmitters using the same frequency, blasting them out of the sky and interrupting the controls to their plane.
This became a problem once people started coming together to fly and the RC hobby became more widespread. I have a couple of these transmitters, which actually have a slot where you need to insert a special crystal oscillator to select which frequency the transmitter uses! In the old days of the RC hobby when airplanes were the only option, most RC transmitter/receiver systems had a fixed operating frequency. The need for more bandwidth in the 5.8 GHz range is further compounded by the fact that our analog FPV systems usually aren't frequency-hopping. This is critical because video transmission requires several orders of magnitude more data to be sent than RC controls and telemetry do because it sends entire pictures instead of a few numbers per transmission. With increased frequency comes higher bandwidth and reduced latency, which is to say that the 5.8 GHz band accessible to us can support more data throughput at a lower latency than the 2.4 GHz band. Especially in the case of FPV video, available bandwidth and interference issues become more of a concern than pure range. This would make it sound like lower frequencies would always be better, but this is not the case. In general, higher frequency transmissions will not be able to travel as far and penetrate as many obstacles as lower frequencies. Probably the most well-known tradeoff in RF is that between frequency and penetrating power. People in our hobby have tried nearly everything under the sun. As is discussed in this Oscar Liang article, FPV hardware exists for all different kinds of frequency bands, stretching from 900 MHz to 5.8 GHz, with 5.8 GHz being the most popular today.
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